Dimmer switch



May 19, 1942. R. H. HILL 2,283,630

DIMMER SWITCH Filed Nov. 18, 1939 M nn!!! INVENTOR Hubert/i175]! a I MIM- I u ATTORNEYS Patented May 19, 1942 2,283,630 I DIMMEB swrrcn Robert R. Hill, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 18, 1939, Serial No. 305,097

6 Claims.

This invention relates to improvements in electric switches, and more particularly to switches of theratchet type which may be operated by foot pressure.

An object of the invention is to simplify the switch structure, to reduce the number of parts, to facilitate the manufacure of the individual parts and their assembly.

Another object of the invention is the provision of a relatively cheap and economical switch structure of the ratchet type operated by a plunger which may be readily assembled, and the parts of which are almost entirely formed from sheet metal stampings, requiring no machining or finishing operations.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. l is an elevational view of the switch structure of the present invention.

Fig. 2 is a view corresponding to Fig. 1 and partly in section with the terminal plate and the movable contact of the switch mechanism removed.

Fig. 3 is a sectional view taken substantially on line 3-3 of Fig. 2 with the terminal plate and the movable contact assembled with the switch housing.

Fig. 4 is an enlarged sectional view taken on the line 4--4 of Fig. 2.

' Fig. 5 is a plan view of the movable contact assembly.

Fig. 6 is a development view of the switch elements, shown in elevation and the elements of actuating mechanism in section, the elements being projected upon a single plane to illustrate the relation of the cooperating parts.

Referring to the drawing, the switch embodying the present invention comprises a mounting plate provided with extruded openings 2|, preferably threaded to receive means for attaching the plate 2| to a floor board, not shown, of a vehicle. The plate supports a tubular member or sleeve 22 on the upper surface thereof. The sleeve 22 is provided with a plurality of depending tongues 23 which are adapted to extend through openings formed in the plate and then bent over against the bottom side of the plate 20 to attach the sleeve to the plate, see Fig. 3.

The plate 20 supports a switch housing 25 on the lower surface thereof. The housing 25 is provided with a plurality of angular cars 25, each ear having an opening to receive a projection 21 struck from the plate 25. The projections are piened over to attach the housing 25 to the plate 20. The housing 25 is provided with a flat back plate 20.

A pivot stud or post is attached at one end to the back wall 28. The stud has an enlarged portion or collar 3|. In this instance the collar is adjacent the flat wall 25. A plunger 33 stamped'from heavy sheet metal, is formed with an enlarged portion 34 and a reduced portion 35 to form shoulders 35. The enlarged portion 34 of the plunger is provided with an elongated slot 31 and a projection 38 on one side of the slot. The free end of the projection is tapered as at 39, see Figs. 4 and 6. The plunger 33 is guided by the housing 25 for straight line movement. This is accomplished partly by the collar 3| of the stud 35 and partly by the reduced portion 35 passing through the rectangular opening 29 of the mounting plate 20. The reduced portion 35 of the plunger 33 is attached at its upper end to a cap 40 and the plunger 33 is maintained in its normal position, shown in the drawing, by a spring 4| surrounding the reduced portion 35 and located between the plate 20 and the cap 40. The shoulders 35 which limit the outward movement of the plunger are maintained normally against the under side of the plate owing to the compression put upon the spring 4|.

A driving ratchet member adapted to be driven by the plunger is mounted upon the stud 30. The driving ratchet member comprises a metal disc or plate 45 stamped from sheet metal. In the present instance the disc is formed with six straight edges 41 which serve as ratchet teeth. The straight edges are formed by striking out sections of the disc outwardly from the general plane of the disc to form tongues 45. The tongues 48 are arranged in a circular row and are provided each with a tapered portion 49 that is complementary to the tapered portion 39 of the projection 35. The disc 45 is also provided at its periphery with an ear 5!! bent at right angles to the general plane of the disc. When the disc is mounted upon the shaft the projection 38 will extend into one of the openings formed by the struck-out tongues 48 of the disc, with the projection 38 engaging one of the straight edges 41. The tapered portion 39 of the projection .38 will be in parallelism with the tapered portion 49 of a struck-out tongue 48.

A contact assembly 50 is mounted on the stud 35. This assembly 59 comprises a disc 5| of insulating material having a notch 52 on its periphery to receive the tongue 50 of the driving ratchet member 45. The front face of the disc 5| supports a movable contact plate 53 having three arms 54 extending radially from a central portion 55. Each arm 54 is deformed to provide a channel 55 which operates as a ratchet tooth.

The open end of the housing is closed by a nonconducting cover or terminal block 81 which is provided with notches 83 for receiving tangs 69 extending from the housing 25. As shown in Fig. 1, these tangs 59 may be bent against the outer surface of the block 61 in order to attach the block to the housing 35. The block supports four live terminals 10, ll, 12 and I3 and two dummy terminals 14, each terminal having a rounded head 15 which is adapted to fit into each of the deformations or channels 66 of the arms 34. The terminals are arranged in a circular row and spaced 60 apart. The rounded heads 13 cooperate with the channels 68 to restrain movement of the movable contact assembly to the right as illustrated in the development view, Fig. 6.

The terminals Ill and II are connected by a single strap 16; and the terminals I3 and 13 are connected to straps I8 and 19, respectively. This type switch is especially adapted for dimming head lights of an automotive vehicle. When the switch is so used, the strap 16 is connected with a current source, and one of the straps l3 and I9 is connected directly with a bright lamp filament and the other is connected to a dim lamp filament. It is therefore apparent that the bright and dim lamp filaments will burn alternately, due to successive operations of the plunger 33.

A compression spring 30 interposed between the disc 45 and theplate 6| operates in two directions. When the block 61 is assembled to the housing 25 the spring 33 will be compressed. The spring 80 urges the metal disc 45 and the enlarged portion 34 of the plunger 33 toward the back wall 28 of the housing, the back side of the plunger having a sliding engagement with the front face of the back wall 23. The spring 80 also urges the contact assembly 30 toward the closure 61. The spring 80 furnishes the necessary pressure to effect a good contact engagement between the contact arms 84 and the rounded ter minal heads "I5 and yet permits of relative axial movement yieldingly between the contact assembly G and the driving ratchet member 43. The contact assembly 60 will move toward the member 45 when the contact assembly 60 and disc 43 are actuated by the plunger, the round heads 15 forcing the contact assembly 60 axially toward the disc 45. When the plunger 33 is returned to its normal position the contact assembly 30 will remain stationary but the projection 33, through its tapered portion 39, will urge the disc 45 toward the contact assembly until the projection 38 registerswith the next opening formed by a struck-out tongue 48. The pressure exerted by the spring 30 is suflicient to hold the contact assembly against the rounded heads of the stationary terminals and prevent backward movement thereof, due to the fact that three of the rounded heads I of the stationary contacts are located in three channels 66.

The operation of the switch is as follows: When pressure is applied to the cap 40 the plunger 33 will be moved downwardly in a straight line. The projection 38 which engages one of the straight edges 41 will drive the disc 45 in a clockwise direction as viewed in Fig. 2. The disc 45 through the tongue 50 simultaneously drives the contact assembly 60 in the same direction. This clockwise direction is continued until the plunger has reached its extreme downward movement. When this occurs the contact arms 84 will have been moved substantially 60 to bridge terminals ll, ll and 14, see Fig. 6. when pressure is removed from the cap 40, the plunger 33 will move upwardly by the spring 4| but the disc 45 and the contact assembly 30 will remain stationary. As the plunger is returning to its normal position disc 45 is caused to move axially on the stud 30. This is caused by the projection 38. Projection 33 urges the disc 43 to the left as viewed in Fig. 3 until the projection 33 registers with another opening formed by a struck-out tongue portion 43 of the disc 43. When this happens the spring will force the disc 43 against the plunger 33. When the plunger is again actuated downwardly the contact arms 64 will be moved another 60 to bridge terminals Ill, 12 and 14.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A switch comprising a housing having an aperture; a shaft anchored at one end to the housing and having its other end free; a plunger reciprocable through the aperture and guided in a straight line movement by the stud, said plunger carrying a projection having an inclined surface on its free end; a rotatable and axially movable discsupported upon the shaft and having a plurality of equally spaced struck-out portions bent out of the plane of the disc to provide a series of abutments arranged in a concentric circle and successively engageable by the projection whereby said disc is rotated in one direction only by the projection upon movement of the plunger in one direction, said struck-out por-' tions being bent at an angle with reference to the incline on the projection so as to move the disc axially away from the plunger upon retraction of the plunger, a spring surrounding the shaft to maintain the disc in operative relation to the projection; a set of relatively fixed contacts and a movable contact rotatively supported by the shaft, said contacts having cooperating provisions whereby the movable contact can rotate only in one direction; and means for transmitting movement from the disc to the movable contact in said one direction of rotation.

2. In an electric switch the combination of a plurality of fixed contacts; a rotatable and axially movable bridging member, said fixed contacts and bridging member having provisions cooperating with each other to restrain rotary movement of the bridging member in one direction; a rotatable and axially movable disc spaced from the bridging member and supported in axial alignment with respect to the bridging member, said disc having a. series of spaced abutments; resilient means disposed between the bridging member and the disc; a slidable driving connection between the bridging member and the disc; a reciprocable member guided for straight line movement; a projection carried by the reciprocable member and engageable successively with the abutments for rotating the disc in one direction of rotation only when the reciprocable member is moved from the normal position, said proiection having provisions to move the disc axialy in one direction compressing the spring to hold firmly the restraining relation between the bridging member and the fixed contacts as the reciprocable member returns towards its normal position, said resilient means expanding after predetermined movement of the reciprocable member toward its normal position to move axially the disc in the opposite direction so that another abutment will be in operative relation with the projecting means.

3. In an electric switch the combination of a housing having a wall provided with a bearing surface; a stud carried by the wall; a reciprocable plunger slidably supported by the housing and having its rear face in contact engagement with the bearing surface wall and guided in a straight line movement by the stud; a lug carried by the front face of the plunger and having an inclined surface on its free end; a rotatable and axially movable disc supported by the stud, said disc having a series of spaced depressions providing shoulders and inclined surfaces complementary to the inclined surface on the lug, said shoulders adapted to be successively engaged by the lug; a plurality of fixed contacts; a rotatable and axially movable contact supported by the shaft; resilient means disposed between the movable contact and the disc, said resilient means urging the movable contact toward the fixed contacts and maintaining an operative relation between the lug and one of the shoulders holding the plunger in contact engagement with the bearing surface wall, the movable contact and fixed contacts having provisions co-acting to restrain rotary movement of movable contact in one direction but permitting the movable contact to move axially on the stud and rotate in another direction; a slidable drive connection between the movable contact and the disc; means for actuating the plunger in one direction from its normal position causing the lug to rotate the disc in one direction; and spring means for returning the plunger to its normal position whereby the inclined surfaces on the lug and disc respectively cooperate to move the disc axially on the stud compressing the resilient means to hold firmly the movable contact in engagement with the stationary contacts to restrain rotation of the movable contact and the disc as the plunger moves toward its normal position, said' resilient means then expanding when the plunger has moved a certain distance toward its normal position to move the disc axially toward the plunger to place another shoulder in operative relation with the lug.

4. In an electric switch the combination of a plurality of fixed contacts; a rotatable and axially movable carrier; a bridging member drivingly supported on one face of the carrier. said bridging member and contacts having provisions cooperating with each other to restrain rotary movement of the carrier in one direction; a rotatable and axially movable disc spaced from the carrier having a plurality of spaced abutments, means carried by the disc having a slidably driving connection with the carrier whereby the disc and carrier rotate together; a spring disposed between the disc and carrier for urging the disc and carrier in opposite directions; and a springretractedplunger having camming means provided with a shoulder adapted to engage successively the abutments to rotate the disc'step-bystep in'one direction upon a forward movement of the plunger, said camming means being operative on'the'return movement of the plunger for moving the disc axially to compress the spring to hold firmly the retaining relation between the bridging member and the contacts.

5. In an electric switch the combination of a plurality of fixed contacts provided with headed portions; a contact carrier rotatable and axially movable with respect to the contacts; a contact plate supported onone face of the carrier and having a plurality of spaced radial arms each provided with a shouldered portion adapted to engage the headed portion of the contacts to restrain rotary movement of the carrier in one direction while permitting the arms to slide over the head in the opposite direction; a rotatable and axially movable plate supported in axial alignment with the carrier; a series of abutments and a series of cams carried by the plate; resilient means supported between the carrier and plate for urging same axially in opposite directions, said spring permitting the carrier to move axially to allow the arms to slide over the head when the carrier is rotated in one direction; means carried by the plate havinga slidable driving connection with the carrier whereby the carrier and plate rotate together but permitting axial movement relative to each other; a springretracted plunger supported relative to the plate; a projection carried by the plunger, said projection engaging the abutments successively to drive the plate step-by-step in one direction of rotation upon movement of the plunger in one direction, said radial arms sliding over the headed portion of the contacts and moving the carrier axially to compress the spring to maintain firmly the driving relation between the projection andthe abutment so engaging. said projection cooperating with one of the cams upon return movement of the plunger to move the plate axially toward the carrier to compress the spring to hold firmly the shoulder of the arms against some of the terminal heads.

6. In an electric switch the combination of a plurality of fixed headed contacts; a contact carrier rotatable and axially movable with respect to the contacts; a contact plate supported on one face of the carrier and having a plurality of spaced radial arms adapted to slide over the heads of the contacts in one direction of rotation, 7

said arms each having a shoulder portion cooperating with the heads of the contacts to restrain rotary movement of the carrier in the op posite direction; a rotatable and axially movable plate supported in axial alignment with the carrier; a series of abutments and a series of cams carried by the plate; means associated with the plate having a slidable driving connection with the carrier whereby the carrier and plate rotate together while permitting axial movement rela tive to each other; a spring supported between the carrier and plate for urging them axially in opposite directions; a spring-retracted plunger supported relative to the plate having a projection engageable successively with the abutments to drive the plate step-by-step in one direction upon movement of the plunger in one direction with the arms of the contact moving the carrier axially to compress the spring in one direction to maintain the driving relation between the projection and the abutment engaged thereby, said projection engaging one of the cams upon return movement of the plunger to move axially the plate to compress the spring in the opposite direction to hold firmly the shoulder I of the arms against certain of the contact heads,

thus preventing the carrier and the plate from rotating in the opposite direction as the plunger moves in its opposite direction.

ROBERT H. HILL. 

